vickery



Fbs 51p H. "\\N VCKERY .ADJUSTABLE swlTGH'ING MECHANISM Original FiledMarch 19, 1925 inventor'. Harry WVcKerg,

His Attorneg.

Patented Feb. 5, 1929.

UNITED STATES PATENT OFFICE.

HARRY W. VICXERY, OF LYNN, MASSACHUSETTS, ASSIGNOR T GENERAL ELECTRICCOMPANY, A. CORPORATION 0F NEW YORK.

ADJUSTABLE SWITCHING MECHANISM.

Application led March 19, 1925, Serial No. 16,765. Renewed August 28,1928.

My invention relates to time controlled switches for controlling aplurality of translating devices such as lamps and theembodin'lcnthereinafter described is particularly designed forcontrolling illuminated semaphore signals for street intersections wheresignals indicative of go, stop and get ready7 are provided to directtraffic at street intersections. The present invention relates tocertain improvements in the type of switching mechanism described in mycopending application Serial No. 694,142, filed February 20, 1924, whichapplication 1s assigned to the same assignee as the present invention.

A popular type of traiic signal for street intersections comprises asuitable tower or post provided with signals indicative of stop, go andget ready. The stop signals are flashed along one streetwhile the gosignals are flashed along the intersecting street, and vice versa, andthe get ready signal is flashed for each street just before aninterchange in the stop and go signals takes place.

' Usually the traffic conditions change from time to time, and atdifferent times during the day, so that it is desirable to provvidesimple means for changing the relative duration of the stop and cgosignals for the two intersecting streets. When the go signal for onestreet is lengthened the stop7 signal for the same street is shortened,while the go signal for the intersecting street is shortened and itsstop signal lengthened.

It will be. appreciated that for each change in this respect it alsobecomes necessary to change the relative time at which the get readysignal for each street will operate since this Asignal must operate justbefore each operation of the stop and go signals.

IMy invention relates to a simple switching mechanism whereby thesechanges may be readily accomplished by a traffic oliicer or other'authorized person without the use of tools or eXtra parts. My improvedswitching mechanism has the further desirable feature of automaticallyand correctly changing the relative time of operation of the get readysignal with respect to the stop and go signals when any change in therelative duration of the last mentioned signals is made.

The features of my invention which are believed to be novel andpatentable will be pointed out in the claims appended hereto. For abetter understanding of my invention reference is made in the followingdescription to the accompanying drawing in which Fig. 1 shows aperspective view of the assembled switch mechanism, Fig. 2 a sectionalview of an adjustable cam shaft and friction clutch used in themodification shown in Fig. 1, and Fig. 3 is a schematic showing of theoperating parts of the switch mechanism together with the circuitconnections.

In Fig. 1, represents a base for supporting the various parts of theswitch mechanism in their proper relation. 11 represents a suitabledriving motor for operating the switch. I prefer to use a self startingsynchronous motor for this purpose since then the signaling device maybe synchronized with other signaling devices located at different streetintersections of the same street system in accordance with the teachingsof copending application, Serial No. 4,580. filed January 24, 1925,entitled Traflic signaling system, Halvorson and Vickery, whichapplication is assigned to the same assignee as the present invention.The speed of the motor is reduced to the desired value by means ofgearing contained within the gear casing 1Q and drives a gear wheel 18meshing with a gear wheel 14 connected by shaft 15 to the operatingmechanism of the switch.

Although I do not wish to be limited thereto, I prefer to use. mercurytube switches because of their reliability, and three such switches arerepresented at 16` 17 and 1S. Switch 16 is tiltablv mounted with a shaft19, as represented in Fig. 3, and switches 17 and 18 are tiltablymounted with a shaft 20. The shafts 19 and 20 are hollow and turn on asupporting rod 21. Between the motor driven shaft 15 and the mercurytube switches are cams and cam levers for tilting the tubes to open andclosed position in the desired sequence which will now be described.

Secured to the operating shaft 15 is a cam 29. which cooperates with acam lever 28 for ltilting tube 16. Also secured to shaft 15 is a cammember 24 cooperating with a cam lever 25 for tilting tubes 17 and 18.Mounted on shaft 15 is a hollow shaft 26, which shaft Acarries a secondset of cam members 27 and 28, also cooperating with cam levers 23 and 25respectively. The cam levers are at all times held down into contactwith their respective cooperating cam surfaces by springs 29. Cam shaft26 is ordinarily held in fixed relation with operating shaft 15 by afriction clutch. The friction clutch arrangement lis best seen in Fig.2, and comprises a plurality of pins 30, a collar 31 for supporting thepins, and a compression spring The pins 30 extend through openings inthe bushing or hub 33 of cam member 28, and bear agalnst the inner sidesurface of caml member 24. The collar 31 is free to slide back and forthon shaft 26 and is pressed towards hub with the pins 30 makingfrictional contact on cam member 24 by means of the spring 32 which iscompressed between the collar 31 and t-he hub 34 of Cam 27.

It will thus be seen that cam members 22 and 24 are directly secured toshaft 15 and cam members 27 and 28 are directly secured to shaft 26 andthat normally they will all be driven together due to the frictionclutch. However, the shaft 26 and with it cam members 27 and 28 maybeadjusted with respect to shaft 15 andcam members 22 and 24 by simplyrotating shaft 26 on shaft 15 by hand, one of the cam members 27 or 28serving as a hand lever for this purpose.

Attention is directed to the shapes of the cams, the arrangement beingfor counterclockwise rotation. It is seen that both cams 22 and 27 aresimilar and each will cause a tilting of tube 16 in both directions. Cammember 24, as represented in the drawing, 'is arranged to lower camlever 25 to tilt tubes 17 and 18 in one direction while cam member 28 isarranged to raise lever 25 to tilt tubes 17 and 18 in the oppositedirection. Cam members 24 and 28 may thus be termed a single adjustablecam for operating cam lever 25. `lVhenever cam member 28 is adjustedwith respect to cam member 24, cam 27 is similarly adjusted with respectto cam 22, and this feature produces the desired automatic adjustment ofthe get ready signal to maintain the desired sequence of operation whenthe relative durations of the start and stop signals are changed.

The switches 17 and 18 are mounted on shaft 20 in such a way that in theraised position of the cam lever one switch is open and the other isclosed while the reverse condition of the switches exist when the camlever is in its lower position. When moving from one position to theother the adjustment is such that the opening of one switch occurssimultaneously, or substantially simultaneously with the closing of theother switch, and vice versa. These switches are thus opened and closedin reverse sequence. 1 have found that the slight jar incident to thedropping of the-cam levers into the various depressions in theirrespective cams assists in the breaking of the contacts in all themercury tube switches scheduled to take place at such instances. Theraising of cam lever 25 is more gradual than the lowering due to thenecessity of making the raising surface of the cam a sloped surface, andif it were not for the slight jar incident to cam 23 dropping off cam 27the lmercury in tube 17 might cling to the electrodes and prolong theclosure when that tube is gradually tilted to the opening condition bycam surface 41. The jarring due to the dropping of the cam levers thushelps to produce the exact timing of the various switching operationsand makes it unnecessary to provide excessive tilting ofthe switches.

Before reviewing the operating of the switch mechanism, it will bedesirable to mention the circ-uit connections shown in Fig. 3. 35represents an electric distribution circuit for s'uj'iplying energy forthe motor and for the signal lamps. It will be an alternating currentcircuit where synchronous motors are used. The field 36 of motor 11 isrepresented as connected across the circuit 35. 37, 38 and 39 eachrepresent a lamp or group of lamps for flashing the signals. These lampsare connected across circuit 35 through the three mercury tube switches;16, 17' and 18. respectively. 37 represents the get ready signal. 38represents the go signal for one street and the stop signal for theintersecting street while 39 represents the stop signal for the firstmentioned street and the go signal for the intersecting street. Asrepresented in Fig. 3, switches 1G and 18 are tilted to the circuitclosing positions, and switch 17 is tilted to the circuit openingposition, and accordingly signals 37 and 39 will be energized. In thisposition of the mechanism, and assuming the apparatus is in operation,cam 22 has just raised lever 23 to close the get ready signalingcircuit, indicating` that a change in direction of traliic flow is totake place. lVith the continued rotation of the cams in the directionindicated by the arrow, cam lever 25 will drop off the. step 4l) in itscam. and cause tubes 17 and 18 to tilt to the right, thereby closingsignaling circuit 38 and opening signaling circuit 39. Simultaneouslycam lever 23 will drop from cam 22 and tilt tube 16 to the right,dcenergizing the get ready signal 37. This condition will continue untilshaft 15 has made approximately 1/4th of a revolution, with theadjustment represented, when cam 27 will next raise lever 23 to tilttube 16 back to closed position to energize the get ready signal 37.Shortly thereafter lever 25 will have been raised by the surface 41 ofcam member 28 to a. posit-ion where switch 18 will close and switch 17will open and simultaneously with this operation lever 23 will drop fromcam 27 to again open the getV ready signaling circuit. This conditioncontinues until cam 22 has again raised lever 27 to close the get readysignaling circuit, thus completing the lll) cycle of changes desired forthis adjust-ment. Now let us assume that it is desired to make the stopand go signals of equal duration on both streets. Cam meniber 28 issimply moved around to the right until its stepped surface is inalignment with the corresponding surfaces of cam member 24, therebymaking the operation of signals 38 and 39 of equal duration.Simultaneously, with this adjustment, cam 27 is also moved an equaldistance around to the right so that its proper time relation isautomatically n'iaintained for the new adjustment.

Now let up assume it is desired to make a still greater change in thesame direction,

that is, make the duration of signal 39 shorter than that of 38. Cam 28may be adjusted still further to the right so that now lever 25 dropsofi' its stepped part instead of ofi' member 24, and lever 25 is raisedby member 24 instead of by member 28. While this produces the desiredchange in the duration of signals 38 and 39, it will be seen that thecams 22 and 27 no longer are properly timed, and to correct this it willbe necessary to loosen the set screws represented at 42 and interchangethe positions of cams 22 and 27 on their respective shafts.

A simpler way of making the duration of signal 39 shorter than that of38 is to reverse the circuitconnections between these signals andswitches 17 and 18 as by the reversing switch represented at 43 so thatswitch 17 controls signal 39, switch 18 controls signal 38, and use theswitch mechanism as first described. j

lVith this switching mechanism it will be seen that the adjustment ofthe cam members 24 and 28 does three things. It lengthens the durationof one signal, shortens the duration ot another signal, andautomatically changes the time relation of a third signal to correspondto the new adjustment. Tools-oi` additional parts are not required forthe adjustment, and due to the automatic adjustment ot the get readysignal, the liability of making an incorrect adjustment of this signalis eliminated. The adjustment can be quickly made while the device is inoperation and at such a time during the cycle ot' operation as not tointerfere with the signals. If at any time the traiiic conditions becomesutiiciently light as to make the stop and go signals unnecessary` butit is still desired4 to intermittently tlash a precautionary signalindicating a crossing. the reversing switch 43 may be opened leavingonly the signal 37 in operation.

Although I have shown and described my invention in conside able detail,I do not wish to be limited to the specific details thereof, as shownand described, but may use such modifications, substitutions orequivalents thereof as are embraced within the spirit of my invention.

j lVhat I ela-ini as new and desire to secure by Letters Patent ot theUnited States is 1. A switching mechanism comprising a motor, aplurality of switches, switch operating means driven by said motor foropening and closing said switches in a predetermined desired sequence,and common adjusting means included in said switch operating means forvarying the time relation of operation between some of said switches andsimultaneously with such adjustment varying thc relative time otoperation ot another of said switches to maintain the desired sequenceof operation.

2. A switching mechanism comprising a motor, three switches, switchoperating means driven by said motor lor opening and closing saidswitches in a predetermined desired sequence, one switch being openedand closed twice for each opening and closing of the other two switchesand common means for adjusting the time relation between the operationof said last mentioned switches, and simultaneously adjusting the timeot operation of said first mentioned switch to maintain the desiredsequence of operation.

3. A switching mechanism comprising a motor, a pair of switches, meansdriven by said motor for substantially simultaneously opening one ofsaid switches and closing the other and vice versa, a third switch,means driven by said motor for opening and closing said third switch ina predetermined time relation with each corresponding operation of saidother switches, and a common adjusting means for adjusting the relativeduration of closure between said pair of switches and the time otoperation of said third switch to maintain the said predetermined timerelation.

4. A switching mechanism comprising a plurality of pivotally mountedmercury tube switches, an electric driving motor, driving mechanismbetween said motor and said tubes for tipping said switches to open andclosed positions in a predetermined desired sequence, and means in saiddriving mechanism for simultaneously adjusting the relative duration ofthe open and closed conditions of one switch and the relative time ofoperation of another switch so as to maintain the desired sequence ofoperation between them.

5. A switching mechanism comprising a pair of pivotally mounted mercurytube switches, an electric driving motor, driving mechanism between saidmotor and tubes for substantially simultaneously tilting said switchesto open one and close the other and vice versa, a third pivotallymounted mercury tube switch, means driven by said motor for tilting saidthird switch to open and closed position for each correspondingoperation 'of said other switches and in' a predetermined desiredsequence therewith, and common adjusting means for adjusting therelative duration of closure of said pair of switches and the time ofoperdtion of said third switch to maintain the predetermined desiredsequence of operation. l

6. A switching mechanism comprising a driving motor, a pair `of mercurytube switches tiltably mounted With a common shaft, a drivingconnectionbetween said motor and shaft arranged to rotate said shaftback and forth through a'small angle to open and close said switches,the switches being arranged on the shaft so that they open and close inreverse sequence, a third tiltably mounted mercury tube switch, meansdriven from said'motor for tilting said third switch to closed positionjust prior to the closure of either of the other switches and to openposition substantially simultaneously with the opening of either of theother switches, and a single adjusting means for varying th relativeduration of closure of said pair of switches during aI cycle ofoperation and the relative time of operation of said third switch tomaintain the stated operative relation With said other switches.

7. In a switching mechanism, a plurality of pivotally mounted mercurytube switches, stepped cams, cam levers cooperating with said cams fortilting said switches to open and closed positions, means for operatingsaid cams in timedy relation, the arrangement being such that when thecam lever for one switch drops from the step in its cam another switchis timed to open, said parts being structurally united such that the jarincident to the dropping of said cam lever from its stepassists in theopening operation of said other switch.

8. In a switching mechanism, a motor, a pair of switch operating camshafts driven by said motor, each shaft carrying cam members formiimY anadjustable cam, another cam on each shaft and means for adjusting therelative rotative positions of said shafts to adjust said firstmentioned cam and the relative positions of said other cams.

In witness whereof, I have hereunto set my hand this seventeenth day ofMarch, 1925'.

HARRY W. VICKERY.

